Effect of Intracoronary Adenosine on No-Reflow in Patients with Acute ST-Elevation Myocardial Infarction Undergoing Primary PCI: A Randomized Controlled Trial.

No-reflow complicates 7-25% of primary percutaneous coronary interventions (PCI) for ST-elevation myocardial infarction (STEMI) and is associated with adverse outcomes. This trial evaluated whether intracoronary adenosine prevents no-reflow and improves left ventricular function. This single-center randomized controlled trial enrolled 200 STEMI patients undergoing primary PCI. Patients received either intracoronary adenosine (1-2 mg, n=100) or standard care (n=100) after achieving TIMI 1 flow. Primary endpoints were post-procedural TIMI flow grade and myocardial blush grade (MBG). Secondary endpoints included left ventricular ejection fraction (LVEF) and dimensions. Adenosine significantly reduced the incidence (33% vs. 60%, P < 0.001) and improved TIMI III flow (86% vs. 49%, P < 0.001) and MBG III (68% vs. 42%, P = 0.003). Post-PCI LVEF was higher in the adenosine group (42.64±8.92% vs. 38.40±9.34%, P=0.001) with smaller left ventricular volumes. Intracoronary adenosine administered after establishing TIMI 1 flow significantly reduces no-reflow, improves myocardial perfusion, and preserves ventricular function in STEMI patients undergoing primary PCI. In conclusion, intracoronary adenosine administered during primary PCI was associated with reduced angiographic no-reflow, improved reperfusion markers, and more favorable early echocardiographic parameters among patients with STEMI. Given the single-center design and absence of long-term clinical outcomes, these findings should be considered preliminary and require external validation.